What is the difference in spreading center earthquakes and subduction zone?
- Spreading center earthquakes are always shallow, subduction zone earthquakes can be very deep.
- Spreading center earthquakes are typically of lower magnitude than subduction zone earthquakes.
A subduction zone occurs at convergent plate margins where an oceanic plate is going underneath a continental plate or a less dense oceanic plate. A mid-ocean ridge is a divergent plate boundary on the ocean floor with a mountain range and a rift running through the center of it. Sea floor spreading also occurs at mid ocean ridges.
Describe the features of the North Atlantic Ocean bottom that are forming due to sea floor spreading?
There is a mid ocean ridge that forms because the hot magma is lighter (less dense than the colder magma. The ridge is located at the spreading center. There are magnetic anomalies that can be thought of as stripes that mirror each other on either side of the spreading center. There are remnants of the pipes that form from upwelling hot springs (black smokers). There are pillow basalts that form from sudden cooling as it…
The US Geological Survey (USGS) National Earthquake Information Center records statistics for earthquakes in the US and worldwide. Between 2000 and 2011 the average number of earthquakes in the US was 3,820 per year that are magnitude 2.5 or higher. The majority of those earthquakes in the US are in Alaska and California with Hawaii in third place. http://earthquake.usgs.gov/earthquakes/states/top_states.php
According to the U.S. Geological Survey (USGS) National Earthquake Center there the average number of earthquakes in the US was 3,820 per year that are magnitude 2.5 or higher, which is on average 73 earthquakes per week. Over the 7 days there were 92 measured earthquakes in the US with magnitude 2.0 and higher.
Since gravity is produced by mass, the center of mass is also the center of gravity. The only difference between these two concepts is that mass is a more basic quantity, so the center of mass would also be the center of inertia, as well as the center of gravity. In practice, these terms can be used interchangeably.
The difference between an institute and a training center is the length of time the student has to study there to gain a degree. Another difference might be that the institute offers several different classes and the training center has only one type of training. A truck driver school might be a training center if it is separate from the institute.
How does differences in density and temperature provide some of the force needed to cause sea-floor spreading and subduction?
Temperature differences in the mantle cause convection currents. These currents cause molten rock to erupt through the valley that runs along the center of the midocean ridge. As more material erupts, the sea floor spreads, cools, and becomes denser. The denser material sinks back into the mantle when it reaches a trench.